Employee login

  1. forgotten?
  • News and Publications
  • News
  • Dec. 2020 - Expert interview with Martin Hummel, Programme Manager for the worldwide S/4Hana conversion at Hella GmbH & Co. KGaA

Expert interview with Martin Hummel, Programme Manager for the worldwide S/4Hana conversion at Hella GmbH & Co. KGaA

Greenfield or Brownfield - the decision for an ERP migration or upgrade seems to be made easily and quickly, depending on the initial situation. But a closer look and at the level of detail reveals that the SAP world is not black and white either.


If one comes from a "tidy", up-to-date and functionally well-fitting ECC world, the brownfield approach, a purely IT conversion of the ECC system to S/4 on HANA, is obvious.


On the other hand, one will have to ask oneself for the whole project whether one has not been deprived of the chance of renewal by adopting processes and programming that have "grown" over a long period of time.


In practice, we at admoVa have found out with our customers that, once started, changes very quickly become "bigger circles" and more complex than planned. Mastering project complexity, focusing on (the right) processes, consistent change management (also in IT) are important criteria for success.



Read our interview with Martin Hummel, who works at HELLA GmbH & Co. KGaA in Lippstadt, who is responsible for programme management for the SAP S/4Hana changeover in the group.


Expert interview with Martin Hummel, Hella GmbH & Co. KGaA

Mr. Hummel, we have known each other for many years from different projects. SAP S/4HANA is the successor of the previous core product of SAP. The S stands for simple, the 4 for the fourth product generation and HANA for the underlying database technology. Is the new SAP S/4HANA really as revolutionary as you read, or is S/4HANA more of a "recycled product" in a new guise?


Martin Hummel: At first glance you really have to look for the new functionalities. And whether these will always offer an advantage will have to be established first. But I think that in connection with the dramatically streamlined data structure, HANA database, Fiori Apps and the constant further development of the system you can already generate a lot of optimisation.


Jens Rittscher: In your opinion, what is the innovative contribution of S/4HANA? Is it rather technically based, are there new business functions, process support ( e.g. finally a finite capacity planning in the PP environment (production planning)) or does the innovation lie in a groundbreaking system performance?


<Martin Hummel: Unfortunately, we have not yet been able to experience the "groundbreaking system performance" live, as we are still in the process of making the change. But we expect a lot from real-time MRP and ad hoc reporting.


<b>Jens Rittscher: Nevertheless, the migration from SAP Business Suite 7 to S/4HANA involves considerable costs. SAP promises to provide mainstream maintenance for core applications of SAP Business Suite 7 until the end of 2027 and then to offer optional extended maintenance until the end of 2030 (see [1]). Why, for example, should our customers switch now, or why should they be considering switching now?


Martin Hummel: The changeover needs to be well considered and prepared. Even if, for whatever reason, you delay it, you should always have an up-to-date roadmap in mind so that you don't experience a rude awakening and end-of-life panic. We have also found that if you really plan major changes in processes and/or SAP landscape, the conceptual work takes a considerable amount of time.


Jens Rittscher: Migration approaches are now "coded" by experts using "green field", "brown field" and other colours [2]. Are these colour comparisons only a marketing instrument to present technically complex facts in a management compatible way, or are there real differentiating features?


Martin Hummel: From my understanding, without having the practical experience in both approaches, the differences are in any case significant. We are currently in the middle of a brownfield conversion and are experiencing that it can be done very efficiently.


Jens Rittscher: From our experience there is no "generally accepted best practice", no black and white approach for ERP migrations/upgrades. But how do you manage the complexity and the effort of the migration in a project?


Martin Hummel: It will not be possible to keep all processes different or realign them. In fact, it will simply be too complex and too costly. ABER With a reasonable process clustering and concentration on processes that promise the greatest benefit, I think you will find the right balance between effort and benefit.


Jens Rittscher: A large part of the German industry is technically tackling the topic of the migration approach on the recommendation of various integration houses. First of all, the technical fit of the system to be migrated is checked and then a complexity assessment of the migration project is made. How do you evaluate this approach?


Martin Hummel: In my view, this depends very much on the initial situation. If I have done "my homework" in the past and have continuously developed ERP landscape and processes, this is certainly a possible approach. Unfortunately, I fear that this will not be the case so often and that in many cases we are facing a landscape that has grown over decades. And then, from my point of view, one should take the chance to clean up. A purely technical migration would not have been enough here.


Jens Rittscher: You are responsible for the S/4 migration at one of the largest automotive suppliers. What was your approach to finding the "right approach"?


Martin Hummel: Whether our initial situation was right, the basic direction of our approach was quickly clear. We use both brownfield and greenfield. In our greenfield areas, the more complex task was to determine the extent of the green and the resulting potential. Fortunately, our management has consistently supported this approach and is committed to its implementation.


Martin Hummel

After many years in SAP-related organisational consulting, Mr Hummel has been in charge of programme management for the worldwide S/4Hana conversion at Hella GmbH & Co. KGaA



Copyright und Trademark remarks

  • SAP® is/are the trademark(s) or registered trademark(s) of SAP AG in Germany and in several other countries.
  • SAP S/4HANA® is/are the trademark(s) or registered trademark(s) of SAP AG in Germany and in several other countries.
  • SAP Business Suite 7® is/are the trademark(s) or registered trademark(s) of SAP AG in Germany and in several other countries.


Literature and cross references

[1] https://news.sap.com/germany/2020/02/wartung-s4hana-sap-business-suite-7/
SAP sagt die Wartung für SAP S/4HANA bis Ende 2040 zu. Gleichzeitig wird SAP die Mainstream-Wartung für Kernanwendungen der SAP Business Suite 7* bis Ende 2027 bereitstellen und anschließend eine optionale Extended-Wartung bis Ende 2030 anbieten.Letzte Aktualisierung – 2020-03.12





Are you interested? Contact us if you have any questions.


Your contact at admoVa:


Dr. Jens Rittscher




Limitation of liability for internal content

The content of our website has been compiled with meticulous care and to the best of our knowledge. However, we cannot assume any liability for the up-to-dateness, completeness or accuracy of any of the pages.

Pursuant to section 7, para. 1 of the TMG (Telemediengesetz – Tele Media Act by German law), we as service providers are liable for our own content on these pages in accordance with general laws. However, pursuant to sections 8 to 10 of the TMG, we as service providers are not under obligation to monitor external information provided or stored on our website. Once we have become aware of a specific infringement of the law, we will immediately remove the content in question. Any liability concerning this matter can only be assumed from the point in time at which the infringement becomes known to us.

Limitation of liability for external links

Our website contains links to the websites of third parties (“external links”). As the content of these websites is not under our control, we cannot assume any liability for such external content. In all cases, the provider of information of the linked websites is liable for the content and accuracy of the information provided. At the point in time when the links were placed, no infringements of the law were recognisable to us. As soon as an infringement of the law becomes known to us, we will immediately remove the link in question.


The content and works published on this website are governed by the copyright laws of Germany. Any duplication, processing, distribution or any form of utilisation beyond the scope of copyright law shall require the prior written consent of the author or authors in question.

Data protection

A visit to our website can result in the storage on our server of information about the access (date, time, page accessed). This does not represent any analysis of personal data (e.g., name, address or e-mail address). If personal data are collected, this only occurs – to the extent possible – with the prior consent of the user of the website. Any forwarding of the data to third parties without the express consent of the user shall not take place.

We would like to expressly point out that the transmission of data via the Internet (e.g., by e-mail) can offer security vulnerabilities. It is therefore impossible to safeguard the data completely against access by third parties. We cannot assume any liability for damages arising as a result of such security vulnerabilities.

The use by third parties of all published contact details for the purpose of advertising is expressly excluded. We reserve the right to take legal steps in the case of the unsolicited sending of advertising information; e.g., by means of spam mail.



S4/Hana Migration
Experts Interview with Martin Hummel - Hella GmbH & Co. KGaA Read more!


admoVa - receives award "Focus Money 2021

Read more ...